1. Field of the Invention
The present invention relates to the field of display technology, and more particular to an organic light-emitting diode (OLED) encapsulation glovebox.
2. The Related Arts
Organic light-emitting display (OLED) has various advantages, such as being self-luminous, low drive voltage, high luminous efficiency, short response time, high clarity and contrast, almost 180° view angle, wide range of operation temperature, and easy realization of flexible displaying and large-area full-color displaying, and are considered the most promising display devices.
An OLED device is generally made up of a substrate, an anode arranged on the substrate, a hole injection layer arranged on the anode, a hole transport layer arranged on the hole injection layer, an emissive layer arranged on the hole transport layer, an electron transport layer arranged on the emissive layer, an electron injection layer arranged on the electron transport layer, and a cathode arranged on the electron injection layer. The principle of light emission of an OLED display device is that when a semiconductor material and an organic light emission material are driven by an electric field, carrier currents are injected and re-combine to cause emission of light. Specifically, the OLED device often uses an indium tin oxide (ITO) electrode and a metal electrode to respectively serve as the anode and cathode of the device and electrons and holes, when driven by a predetermined electrical voltage, are respectively injected from the cathode and the anode into the electron transport layer and the hole transport layer such that the electrons and the holes respectively migrate through the electron transport layer and the hole transport layer to get into the emissive layer and meet in the emissive layer to form excitons that excite light emissive molecules to emit light, the later undergoing radiation relaxation to give off visible light.
A contemporary mainstream production process for OLED devices is vapor deposition, wherein an organic small molecule material is heated in a vacuum chamber to sublimate or melt and vaporize into vapor of the material that deposits, through openings of a metal mask, onto a glass plate to form the OLED device. Afterwards, encapsulation of the OLED device is conducted in an OLED encapsulation glovebox through an encapsulation process that involves coating a resin frame on a glass or metal back lid.
FIG. 1 is a cross-sectional view showing a conventional OLED encapsulation glovebox, and FIG. 2 is a schematic view illustrating a structure of connection between a box body and a box door. As shown in FIGS. 1 and 2, the OLED encapsulation glovebox comprises a box body 100, a box door 200 that is hermetically connected to the box body 100, and a single sealing ring 300 arranged between the box body 100 and the box door 200. The box body 100 comprises an opening 110 and a first sealing face 120 located around the opening 110. The box door 200 comprises a second sealing face 210 that is arranged opposite to the first sealing face 120. The sealing ring 300 is arranged between the first sealing face 120 and the second sealing face 210 to hermetically connect between the box body 100 and the box door 200.
The box body 100 has an interior that is generally filled with nitrogen gas to maintain a strongly high positive pressure with respect to the outside (namely the pressure in the interior of the box body 100 is far greater than the external atmospheric pressure) in order to prevent external moisture and oxygen from penetrating inwards to thereby provide an excellent moisture/oxygen isolated environment for encapsulation of an OLED device. However, since the box body 100 has a relatively large size, the cost for maintaining the positive pressure is high. Further, since there is only one single sealing 300 provided between the box body 100 and the box door 200, breaking or apertures, once occurring in the sealing ring 300, would lead to invasion of external moisture and oxygen to affect the performance of encapsulation of the OLED device.